Improvement in the processes for the manufacture of paper



UNITED STATES 'rmv FFIGE.

JOHNMJ ALLEN,*OF MARION, MASSACHUSETTS.

Specification forming part of Letters Patent No. 150,504, dated May 5, 1574; application filed April 16, 1s74.

To all whom it may concern:

Be it kn'own'that I, JOHN M. ALLEN, of

Marion, in the county of Plymouth and State of Massachusetts, have invented a new and useful Process for the Manufacture of Paper; and I do hereby declare that the following is a full and exact description" of the same, reference being had to the accompanying drawings and to the letters of reference marked thereon.

The object I have in view is'to obtain from the barkof coniferous trees a pulp'suitable for merchantable paper, for all ordinary mercantile purposes, of fine texture, tough fiber,

and good color, without the use of alkalies or acids, and at ared'uced cost of manufacture; and my invention therein 'consists'in the peculiar process by which the tannic properties are extracted from the bark of coniferous trees, and the residuum reduced to a pulp proper for a merchantable paper, without the use of alkalies or acids. It also consists in the paper it self, which is the result of such process.

In order to enable those skilled in the art to make my pulp and paper, I proceed to describe how I make the same.

' a fine and fibrous condition, with sufficient water, into wooden tanks heated by means of pipes other than iron or steel, which cannot be used, as thereby the mass would receive a dark unsalable color.

heated to as great a degree as possible, which degree of heat is maintained as nearly as pos- 'sible throughout this portion of the process. The water is from time to time drawn'off as the boiling continues, and its place supplied with very hot or boiling water. This process of boiling is continued until the water drawn The water is then,

off is clear, or nearly so, and lasts, commonly, from four to ten hours, varying with the material and the quantity used. ,By this means the tannic properties in the bark are nearly or quite extracted. I then place the bark thus treated in a pulp -engine, with the beaters partly raised, and brush itthat is, bruise it without reducing it to pulppassin g through it continuously a stream of clear water, preferably tepid, until all the remaining impurities and tannic properties are entirely exhausted from the mass. I then drop the heaters in the machine, and reduce the stock to a pulp in the ordinary way, except that it requires a longer period of time than it does with common fibrous stock, like hemp or jute.

The stock is then ready to be converted into paper in the ordinary way, and makes a paper light in color, fine and smooth in texture, strong and flexible, and presenting to experts .a diflerent appearance from any other paper in market, so that it can be readily distinguished by the trade.

It is evident that by the ordinary processes of bleaching and calendering a paper may be obtained from the same stock adapted for printing or for writing.

The above process is that which I prefera bly use; but, it being evident that the essenthe injurious affinity of iron or steel, acids or alkalies, with the tannic acids in barks, v

I do not wish to confine myself to boiling the bark in wooden vats, with water heated by pipes other than iron or steel, as the same good results may be attained by the use of vats of metal or other material having no affinity with tannic acid, or the use of pipes ofmaterial havin g no affinity with tannie acids, or by the use of steam in a close and strong vessel having no affinity with tannic acid, or by the use of water highly heated and under great pressure in a close vessel having no affinity with tannic acid. And while I prefer using the various steps enumerated by me in the bruising, shredding, picking, and washing of the bark, it is evident that the same may be accomplished by other means, or by dispensing with some of the steps enumerated by me in this particular, the essential idea being that the bark should be disintegrated and thoroughly washed.

I am aware that it is not new to use spent tan, or the bark of various trees, or even the entire bark of coniferous trees, in the manufacture of paper-pulp, and I do not pretend to have been the first in these particulars. I am also aware that it is not new to macerate bark with water and alkalies, to eliminate the inherent resinous and tannie properties, and I do not pretend to have been the first in this particular. I am also aware that it is not new to macerate bark with water alone, for the purpose of converting its resinous properties into a size, and, after the same is partially pulped, to mix it with hard stock-viz., flax, hemp, and cotton-waste-and then complete the operation of pulping, and I do not pretend. to have been the first in this particular.

coniferous trees has been exhausted of tannic acid by treatment in vessels constructed of material having no affinity for tannic acid, or heated with the use of conducting material But as I do not know that the bark of 7 having no aflinity for tannic acid, and without the use of alkalies or acids, thereby extracting from the bark all the inherent tannic properties in it, and making in a simple and cheap way an excellent quality of paper, I believe that I am the first to have conceived the same and, therefore,

I claim as my invention and desire to secure by Letters Patentr I The process of making paper-pulp, substantially as described, by treating the bark of coniferous trees with steam or water, and without alkalies or acids, thereby exhausting the tannic acid. in vessels having no afiinity for tannic acid.

This specification signed and witnessed this 16th day of April, 1874.

JOHN M. ALLEN.

Witnesses: i

CHARLES THURMAN, R. N. DYER. 

